The earth's crust is at its thickest under the continents or land masses. Here it is on average between 30 to 40 kilometers thick.
Three specific zones of earth are crust, mantle and core. The outer layer is crust. It is quite thin, between 6 and 40 kilometers. The next layer down is the mentle, about 2900 kilometers thick. The outer core, below the mentle is about 2000 kilometers thick. They inner core is about 1300 kilometers.
The major biomes of the world are: Tundra, coniferous forest, deciduous forest, grass lands and Savannas Chaparral, tropical rain forest and deserts. Major biomes of the world.
Biosphere is a term used to describe the parts of the earth and the thin layer of air above its surface that supports life. It is limited to the waters of the earth, a fraction of its crust and the lower regions of the atmosphere. It is also the part where solar energy is used to bring about photosynthesis and other chemical and physical charges.
It is a broad natural assemblage of plants and animals shaped by common patterns of vegetations and climate. Some examples of biomes are forest biomes, desert biomes, grass land biomes or tundra biomes etc.
The biotic factor concerns the organic variable affecting an ecosystem. For example, the changing population of elephants and its effect on the African Savana.
The living components of biosphere such as plants, animals etc. are called biotic components. The non-living components of biosphere such as water, air, stones, etc. are called abiotic components.
Habitat is defined as a localized environment in which an organism lives and which provides for all or almost all of its needs.
The term food pyramid is used to describe the quantities of materials that pass from one kind of eater to another. The word pyramid is used because the amount of energy associated with the food material becomes smaller at every link or upward step.
All food chains begin with green plants because they are the only living things that can produce their own food. Green plants produce food by the process of photosynthesis.
The gradual but continuous change in a community is called ecological succession. If one community disappears, a different kind of community develops in place of the old one.
Animals living in trees are called arboreal such as monkey.
Plants that grow on other plants using them only for support are called epiphytes. They have no roots in the soil. Epiphytes do not parasitize the plants they grow on.
Camouflage is the disguise used by animals to hide from their enemies. Men also use camouflage, particularly in wars. Most animals use camouflage to hide from predators or other animals that prey on them. Camouflaging is done by adopting matching colour to the surroundings, so that one looks like a part of it.
An animal which obtains food by hunting other animals is called a predator.